Question

What is the value of y so that AB with endpoints A(1, y) and B(6, −1) is parallel to CD with points C(1,2) and D(-4,-2)??

Answer 1

can someone help me? i just need the equation on how to do it. I've been stuck on this for an hour

Answer 2

Okay whenever the direction between two pair of points is parallel. The gradient of both of them is same

Answer 3

Parallel lines have the same slope. The slope equation is
\[m=\frac{ y_2-y_1 }{ x_2-x_1 }\]
Plug int he values for each of your segments and set the slopes equal to solve for your "y"

Answer 4

So
\[\large\rm \frac{y_2-y_1}{x_2-x_1} =\frac{y_3-y_4}{x_3-x_4} \]

Answer 5

okay so -1-y/6-1 = -2-2/-4-1 ?

Answer 6

yes

Answer 7

yep

Answer 8

so how do i get y? im still kinda confused

Answer 9

Solve it

Answer 10

-1-y/5 = -4/-5

Answer 11

-1-y/5=-4/-5

Answer 12

yeah i got that

Answer 13

then cross multiply

Answer 14

-5(-1 - y) = -4(5)

Answer 15

-5-5y=-20

Answer 16

-5y=-20+5

Answer 17

-5y=-15

Answer 18

whoa hold up

Answer 19

oh wait am i doing it wrong..?

Answer 20

you just made a mistake distributing. it should be
5 - 5y = -20

Answer 21

ohh i see where i made the mistake

Answer 22

so -5y=-20-5

Answer 23

-5y=-25

Answer 24

-25/-5

Answer 25

y=5?

Answer 26

yep

Answer 27

thank you so much!

Answer 28

(-1-y/5) x 5=(-4/-5)x5
-1-y = -4/-1
-1-y = 4
-y = 5
y = -5

Answer 29

wait so i did it wrong?

Answer 30

You did a mistake
-5(-1 - y) = -4(5)
5+5y = -20

Answer 31

oh @FaiqRaees is right. I messed up the distribution as well

Answer 32

ohhh lol ok thank you so much!!!